Patents

WASHINGTON, Jan. 28—A reduction in farmers’ use of pesticides by as much as two‐thirds, with no loss in food production, is the goal of an electrostatic spraying system that was patented this week. It coats plants while leaving the earth and air unscathed.

S. Edward Law, a faculty member at the University of Georgia's Agricultural Engineering Department, Athens, Ga., was granted Patent 4,004,733 this week for the invention, which is generating much interest among agricultural experts.

A spray nozzle is fitted with a small annular electrode that charges the spray as it is propelled outward by compressed air. The air takes the spray inside plant canopies and in close proximity to stems and leaves, where the small electrostatic charge attracts droplets to the plants.

The saving to farmers in pesticide costs is estimated at more than $1 bilflog annually. In addition pollution from agricultural spraying is reduced. With present techniques perhaps 20 percent of the spray remains on plants. Electrostatic spraying, in contrast, may place 80 percent or more on the target.

A process to help produce composite materials as stiff and strong as metal but much lighter has been invented for the Union Carbide Corporation.

Leonard S. Singer, a corporate research fellow at the company's Parma Technical Center in Ohio, was granted Patent 4,005,183 this week for a method to make high‐strength carbon fibers used in the composites.

“Pitch,” a heavy liquid distillate of coal tar or petroleum, is converted to a liquid crystal phase in the patented process and then is spun into fibers for use in the composite product.

The lightweight products are used in the manufacture of airplanes and missile components, and such sporting equipment as golf clubs, tennis rackets and fishing rods. They are now being evaluated for automotive and computer applications, as well.

The use of pitch in making such carbon fibers has substantially lowered the cost of high‐strength, lightweight composite materials, and Union Carbide expects that, as production increases, prices will drop much further.

Patent Is Issued for Microminiature Devices

Jerome H. Lemelson, president of the Licensing Management Corporation, New York. has invented a process to serve the manufacturers of microminiature electronic devices by forming tiny light pipes, photoelectric cells and laser elements directly on a circuit board.

The procedure for which he was granted Patent 4,005,312 this week, eliminates the need to fabricate the components separately and attach them.

Mr. Lemelson expects his equipment to be used largely in computers, military electronic systems and industrial process controls. He will demonstrate the invention at a trade show in Chicago next month.

Inexpensive Device In Magnetic Fields

The discovery of a new physical effect may facilitate development of a highly compact, inexpensive instrument for measuring magnetic fields—a magnetometer that could be used to locate oil and mineral deposits, find archaeological treasures and conduct scientific research.

The device would be based on Patent 4,005,355, granted this week to William Rapper and Henry Y. S. Tang, who did their research at Columbia University.

Today's, magnetometers, bulky,power ‐ consuming instruments, cost several thousand dollars. The one proposed by Dr. Happer and Dr. Tang would be about the size of a cigarette and in the same price range as a transistor radio.

The planned magnetometer is based on a previously unknown principle: atoms of certain gases at high pressures can show a sharp resonance point, in proportion to an external magnetic field. Present instruments use large, low‐pressure cells.

Resonance in the new device would be measured by stimulating a tiny cell of high‐pressure gas with radio. energy and measuring the frequency at which it absorbed light from a tiny semiconductor laser. This resonance point is dependent on the external magnetic field and serves as a measurement of it.

Dr. Happer is professor of physics at Columbia University, and Dr. Tang is now on the technical staff of Bell Telephone Laboratories. Licenses under the patent are being offered to industry by the Research Corporation, a New York foundation, in accordance with an agreement it has with Columbia University.

To get a copy of a patent, send the number and 50 cents to the Patent and